Sunday, 23 November 2014

Review: The Abbott Freestyle Libre

The Abbott website proudly announces...

The days of routine glucose testing with lancets, test strips and blood are over. Welcome to flash glucose monitoring!

In the small print it expands on this to say that if the Freestyle Libre indicates a rapidly changing level or if it suggests you are hypo (or near hypo) then you should do a finger prick test to confirm.

A finger prick test using a blood glucose meter is required during times of rapidly changing glucose levels when interstitial fluid glucose levels may not accurately reflect blood glucose levels, or if hypoglycemia or impending hypoglycemia is reported but the symptoms do not match the system readings.

What they don't tell you is that you will also need to continue with a finger prick test before driving (and every 2 hours thereafter if on a long drive) to meet current DVLA requirements. In the minutes of the meeting of the Secretary of State for Transport's honorary medical advisory panel on driving and diabetes mellitus, held on Tuesday 14th October 2014, Section 6.1 it states:

The Panel also considered continuous glucose monitoring systems (CGMS) which measure interstitial glucose. At present it was considered that there is too little evidence to suggest that CGMS alone is a reliable measure of glucose levels. They advised that drivers using CGMS must also monitor blood glucose as advised for insulin treated diabetes in the ‘At a Glance Guide to the Current Medical Standards of Fitness to Drive’. This will be reviewed at future meetings as more data becomes available and when there may be comprehensive regulation of such devices.

However there is no doubt that if the readings provided by the Freestyle Libre are accurate, then the amount of finger prick testing will reduce.

So what does Abbott say about accuracy?


The key message they want people to know is that it

Requires no finger prick calibration
This is clearly aimed at highlighting one of the key "benefits" over current CGM systems which require a number of finger prick tests to ensure accuracy of results.

The FAQ also states:

11. Is the accuracy of the sensor consistent over the 14 day wear period?
Yes, the accuracy of the sensor remains consistent for up to 14 days.

In practice I found this not to be the case  which is bitterly disappointing after spending £138.25 on purchasing the starter kit (£133.29 kit + £4.96 postage). Others fortunately have found accuracy not to be a problem (particularly after the first day of use). I will cover my own experiences on accuracy in more detail later.

A closer look at the starter kit



In the box


The starter pack consisted of three boxes: one for the reader and the other two for sensors.

The reader box contained the reader itself, a quick start guide, a user guide, usb cable and charging plug.

Each sensor box contained a sensor, applicator, alcohol wipe and instruction guide.

What's missing?


I was surprised that the reader didn't come with some kind of carrying case and since finger prick testing will still be required it was disappointing (and most probably a missed opportunity) that no finger pricker, lancets, blood or ketone strips were supplied.

Indeed the documentation provided didn't even provide details on how to get your prescription changed to Abbott blood test/ketone test strips - surely something they would want you to do? I can only assume that this was a marketing decision that thought that providing these things didn't sit well with the "routine blood testing is a thing of the past" message.

I was also surprised that a summary wasn't provided on the differences between blood glucose testing and interstitial glucose testing. I'm sure many phone calls to the help desk could (and would) have been avoided if such an explanation had been provided. Most people will naturally want to compare readings between their current method and the Freestlye Libre and if they don't understand the differences in measurement, the timing differences and the clever software being used to try an reduce the time delay then questions are surely going to be asked.

The reader

Comparing sizes
Freestyle Libre vs MyStar Extra
The reader fits comfortably in the hand and can read the sensor through clothing (even a coat!). The determining factor on how discrete scanning will be is based on where you place the sensor but it is certainly less obvious than doing a finger prick test and certainly less hassle - no worrying about washing hands/ensuring they are dry etc.

Described as a touch screen display on their website it seems to be a screen with 12 pressure zones. In the right lighting conditions when you hold the reader at 45 degrees and tilt it slightly towards you it is possible to make out the individual zones. If you perform a self test the last test in the sequence allows you to check that each of these 12 zones is responsive to touch. Unlike the FreeStyle Optium Neo and InsuLinx this seems much more responsive to touch and requires less pressure to be applied on the screen to be acknowledged.

Applying the sensor


It's interesting to note that if you look on the Freestyle Libre website, all of the images show the sensor being placed on the side of the arm yet the documentation provided with the kit suggests the sensor should be placed on the back of the arm.

For my first sensor I selected my right arm, on the side near the back.
For my second sensor I selected the back of my left arm.

With the first sensor I had a dull throb inside my arm where the sensor was inserted for slightly longer than one hour, but there was no pain at all when applying the second sensor.

Initially with the first sensor it felt odd. I could feel my clothes against it. I knew it was there.
Thankfully as time passed I started to accept it more and more and I became less aware of it's presence on my arm. It took a number of days before I was fully comfortable with it and I'm sure part of this process was delayed due to my worry that I might damage it in some way and cause £50 of kit to become worthless. By the end of the two weeks the only times I was truly conscious of the sensor on my arm was when I was washing or drying and during the scanning process... oh and, most annoyingly, when I had an itch under the sensor which couldn't be dealt with due to the lump of plastic on my arm!

I didn't have any of these issues with the second sensor. Indeed sometimes I would be waving the reader around trying to find exactly where I'd placed the sensor!

Day to day usage

MyStar Extra: 4.8 mmol/L
Libre blood test: 5.1 mmol/L
Libre scan: 3.6 mmol/L and stable

In general, I found the Libre to scan consistently lower compared to a blood test (even when using the Abbott test strips).

The example shown here shows the scanned result says I'm hypo (3.6mmol/L) and both the Libre blood test and MyStar Extra blood test says I'm far from it!

In fact the Libre blood test says I'm good to drive under DVLA rules and the MyStar Extra says I need something to eat.

If the DVLA accepted the Libre scan for driving (which thankfully they don't!) I would need to treat and wait 45 minutes before making a journey.

No wonder the small print mentions testing blood when the Libre says hypo!
This is one of the main reasons why I lost confidence in the Libre.

I think it is extremely telling that the insulin calculator can only be used when a blood test has been completed on the Libre and that the calculator is not available when you do a scanned test (even if the directional arrow says stable).


The Reader - User interface niggles


Entering carb and insulin doses takes time!

The reader doesn't remember your background insulin doses, so every morning and evening you have to input the number of units using the up/down arrows starting at 1 unit. When your background dose is 24 units at night that takes time even when you press and hold the up arrow!

It's a similar problem when entering your fast acting insulin doses - it always starts at 1 unit and only goes up by one unit at a time.

Entering carbohydrates has similar frustrations too. It always defaults to 15 grams (that's not even a slice of toast!) - I'm sure that's fine for low carbers but if you plan to have a pizza then it's getting cold by the time you have input all the correct numbers :/

If the numbers jumped by 10 when you press and hold the up or down arrove rather than moving by 1 every time then it would be a lot quicker.
Of course the other option would be to display a numeric keypad but given the limitation of the touch screen this isn't really possible.

Despite the time consuming nature of entering values (I admit it, I was bored!) I've identified that the entry limit on carbs is 200 grams and the limit for an insulin dose is 50 units. I suspect this is more than enough for most people but interesting nevertheless that they've imposed these particular limits.

Maximum amount of carbohydrates
Maximum amount of insulin
If you forget to enter additional information against a reading you have a limited amount of time to go back and add it. If you re-scan or wait too long then it is impossible to put the information in. So if you want that pizza warm and your carbohydrate and insulin dose recorded then you are going to have to compromise. If you don't add the carb & insulin information at the right times then the value of the information provided via the free software is diminished.

When the sensor expires

Boy, you know when the sensor is about to expire! Why? Because it can't stop telling you!

This is one of the most annoying features of the product.

Three days before the sensor expires you get a reminder.

That's great as it gives you the opportunity to re-order a sensor, although given the 3-5 working days for delivery maybe the reminder should be a little earlier?

After that it starts to get annoying and doesn't really seem to have any other purpose than to annoy you. It reminds you at 2 days, then at 1 day...
 ...then hourly...
...and in the final hour (if you scanned every minute) it would remind you every minute!

Quite what they think a customer of the product is going to do at 7 hours to go, or 45 minutes to go, that wouldn't be done if the system didn't remind them I'm not sure, but I can tell you that all it made me want to do is throw the darn thing at a wall. What is particularly annoying is that the warning message is also accompanied with the vibration used to indicate a hyper or hypo situation.

Annoying! Annoying! Annoying! 

If Abbott really feel the need to hassle customers like this then they should at least give the option to click a button that says "Thanks for the reminder. I don't need reminding any more. I'm well aware that the sensor is about to expire!".

Immediately after removal
The sensor
After cleaning

The website, ordering and customer service


In the run up to the release of the Freestyle Libre Abbott tried to whipped up a bit of a frenzy, getting people to register on their site for more information. So it was somewhat surprising to find that ordering was available from the 17th October but people who had registered for more information only got told on the 22nd October - five days later!

To be honest it was most probably a good thing because many people experienced problems with the ordering process. For myself the ordering went through fairly smoothly and I received an email confirming my order... but then it started to go wrong.

Website order information page

I was supposed to get an email providing my tracking number once my order had dispatched but I didn't receive the tracking number until the 24th October, two days after they had tried to deliver it. Indeed the Libre sensor was already in my arm the day before I received that email!

Trying to obtain my shipment information threw up this error
When I saw my order had shipped I tried to use the website to find out my tracking number but clicking on the invoice link also threw up an error. (Thankfully this particular issue has now been resolved but if it had been working at the time I still wouldn't have my tracking number.)

So on the 22nd I decided to ring the customer support number to find out my tracking number - little did I know that whilst I was tried to call them the delivery company was trying to deliver it!

I rang the support number (008000 - 2255 232) provided on the website only to be routed to German only speaking call centre. I tried again and the same thing happened.

I then went to the generic Abbott diabetes website and obtained the 0500 467 466 support number. This thankfully put me through to an English speaking call centre.

The support representative sounded hassled and wasn't particularly helpful. I asked if they could tell me my tracking number given the website said the product had shipped. I was told I'd get an email when it shipped and the gentlemen wasn't interested in the fact that I hadn't received one. He told me none had shipped yet and wasn't interested that people already had them. He told me to wait for the email and made me feel like I was asking an unreasonable question and wasting his time.

He then went to to explain that "many patients have been ringing up..." Whoa! Patient? I'm not a patient of Abbott, I'm a customer and all of the other people ringing up are customers too. I really wasn't impressed with this guy calling me a patient. If I wasn't ringing from an open plan office I would have given him a piece of my mind, hassled call centre representative or not! Luckily for him I was and so I just put the phone down resigned to the fact that Abbott had my money and didn't care if I got what was promised or not.

When I got home I had a card telling me they'd tried to deliver the Libre whilst I was at work - so much for none have been dispatched!



Apparently I was hypo, but given I didn't have hypo signs
and my own meter said I wasn't, I disagree!
When I found out my Libre was reporting bgs about 3mmol/L lower than my current bg meter I dared to ring up customer services again hoping to find out a way to calibrate the results. I wish I hadn't! I finished the call feeling like I'd been called just short of a liar. The attitude was that my own meter must be wrong, my own hypo awareness must be lost and the Libre was telling the truth and I've spent entire afternoons and evenings hypo without realising it.

I had also ascertained that it wasn't possible to do any calibration and Abbott wouldn't entertain any concept of the readings being incorrect unless I tested using their blood test strips in the Libre.

Given they hadn't provided any in the starter pack they said they would send out ten test strips to allow me to test and I'd receive them the following day.

The following day readings were much better (not "perfect" but more acceptable) and I decided to ring up to say so. They weren't interested. At first they thought I was ringing to ask where the test strips where and before I could correct them they were telling me it would be 3-5days before I got them! Tip to Abbott Customer Services - listen to what your customers are saying before responding! When they realised what I was saying they completely lost interest, didn't even want to know my name, just wanted me off the call.

By the time the test strips arrived I was pretty much at the end of the 14 days usage and although I wasn't totally convinced by the accuracy it seemed pointless to check.

I tried them with the second sensor and it seemed like that helped calibrate the readings quicker but that might have just been a coincidence.

Needless to say I didn't bother ringing the customer services line to tell them the numbers of the blood test matched my own meter and not the Libre scan. By this time I'd given up with the attitude of Abbott Customer Services and written off my "investment".

I did however take my Freestyle Libre reports to my DSN who was interested to compare them against the information from my own bg meter that had been downloaded to the DIASEND software they use. She was shocked at the differences and concerned at how often it said I was hypo compared to my own meter. Needless to say she was somewhat underwhelmed by the Libre accuracy too.

Comically if I did want to order a new sensor I can't. When I go through to the checkout process I can't get past the the first step as it now claims my Street Address is greater than 35 characters - it isn't!

Abbott won't let me order a new sensor even if I wanted to!


The Freestyle Libre software


Hats off to Abbott here, the software is very comprehensive and allows you to export data so you can combine it with other data should you wish or create your own reports.

I suspect the biggest challenge for many people may well be in interpreting all the data provided (although some of the reports do give you a dashboard and some helpful suggestions). Unfortunately little help is provided in the manual, instead plenty of "IMPORTANT: Work with your HCP" comments litter the document.


Examples from the user guide


A large variety of reports are available

Conclusion


If you ignore the actual mmol/L values the Libre displays (now that is a bold statement!) the Libre does give valuable insights into bg trends showing the movements due to stress, different foods, exercise etc. It can easily show you if your overnight basal dose keeps your bgs stable... no need for a 3am check, so it does win some points for allowing me to sleep through the night... but no more than 8 hours sleep otherwise there will be gaps in the data collected :)

The proposition (for me) seems to be convenience at the expense of accuracy, but accuracy isn't something I am willing to sacrifice. If Abbott can resolve the questions around accuracy, improve the customer service experience and allow me to order(!) I'll be fighting my way to the front of the queue... but until then, the future for me is finger prick testing!


Other Freestyle Libre blogs